Spring Cloud Gateway MVC is using a single http2 connection to downstream

Describe the bug
If the downstream server accepts http2 and for example offers 100 concurrent streams (tomcat default) the http client in gateway mvc is using up to those 100 streams in one connection, then on the 101st parallel stream, it throws an exception (too many concurrent streams) even when the tomcat would allow a lot more connections (default is 200 tomcat threads). I'm not sure if this is a problem in either JDK, springs RestTemplate or SCG mvc. Somewhere should be a connection pool which uses multiple real connections instead of trying to put everything in a single one.

Sample
Use a route to a default config tomcat (spring boot) with a long enough response time and add up to 101 requests in parallel (or reduce tomcat concurrent streams to a smaller number for easier testing).

Start by reproducing the Gateway MVC route against a default Tomcat with 101 parallel requests and long response times. Then trace the downstream HTTP client and RestTemplate connection handling. Done means requests beyond the downstream HTTP/2 stream limit use additional real connections instead of failing with a too-many-concurrent-streams exception.